High Spatial Resolution Perovskite Fast Neutron Imaging Screen by ³⁵Cl (n, p) Nuclear Reaction

Abstract Fast neutron imaging has emerged as a highly adaptable non‐destructive inspection tool in industrial applications and scientific research. This technique predominantly employs hydrogen‐rich scintillation screens based on the principle of nuclear recoil; however, it suffers from limited spatial resolution due to significant energy diffusion of recoil protons. Herein, a 1D perovskite, Cs₅Cu₃Cl₆I₂ is demonstrated, for fast neutron imaging based on ³⁵Cl (n,p) nuclear reaction. This scintillator features a large area (25 cm²), an excellent light yield (31 597 photons/MeV), and high spatial resolution (1.31 lp mm⁻¹). The reduced energy diffusion of secondary charged particles, resulting from the distinct detection principle of nuclear reaction, contributes to the high spatial resolution. Imaging of a Teflon mold successfully demonstrates its potential for low‐Z material radiography. Combined with outstanding stability and low afterglow, Cs₅Cu₃Cl₆I₂ represents a new class of high‐performance perovskite fast neutron imaging screen based on nuclear reaction principles. This advancement is anticipated to significantly advance industrial non‐destructive testing and nuclear medicine imaging.